textproduct: Quad Cities

KEY MESSAGES

- Today will see more severe storms. There is an Enhanced, level 3 out of 5, risk for severe storms that look to occur in two rounds. All modes of severe weather will be possible.

- Storms will be moving at 50-60 mph so there will be less time than normal to react when a storm approaches. Additionally, storms will be prolific heavy rain producers that may cause flash flooding.

- Strong gradient winds of 30 mph with gusts to 45 mph will be seen today ahead of the front. Behind the front winds may gust up to 50 mph for a period of a few hours.

SHORT TERM /THROUGH TONIGHT/

Issued at 241 AM CDT Thu Jun 11 2026

The next 24 hours will consist of multi-faceted weather risks with several having the potential of being high impact. That being severe storms, fast moving storms, flash flooding and non-thunderstorm winds.

Headlines changes...

The flash flood watch has been extended to the entire area and extended until 7 PM.

Discussion...

The LLJ and moisture transport will continue to strengthen through sunrise. This will allow elevated storms to develop from southeast Nebraska into southwest Iowa and possibly northwest Missouri. The very short term models show this growing upscale into an organized MCS that will move east across Iowa. The arrival in eastern Iowa will be after sunrise and the MCS will begin a transition from elevated to surface based.

Like yesterday there will be a risk of damaging winds this morning through about mid-day. The very short term models differ on when the complex becomes surface based but it will be across eastern Iowa.

Initially the damaging winds may be limited to 55 to 65 mph with large hail. However, once the complex becomes surface based, much higher severe winds become more likely. Indeed, some of the CAMs are starting to suggest small corridors of 70 to 80+ mph winds as the system bows out (indicating the system is surface based). At the same time, brief spin-up tornadoes would also be possible.

Normally the severe risk would go down after the atmosphere gets worked over so thoroughly in the morning.

However, the LLJ will increase through late morning and into the afternoon with the approach of the surface low. Integrated Vapor Transport is progged to increase to over 1200 kg/m/s. The very strong IVT combined with an upper jet of 100+ knots will result in rapid recovery of the atmosphere behind the departing morning storm complex and also promote broad lift for new storm development.

The passage of the surface low from late morning through mid- afternoon will be the time when the tornado risk will be the highest.

All the CAMs develop supercells by mid-day and continue that through mid-afternoon. The position of the warm front across the area will maximize low level turning in the atmosphere and will be key as to where the greatest tornado risk will be located. Any storm riding on or near the warm front will be most at risk for producing tornadoes.

During the supercell phase the primary severe risks will be very large hail and tornadoes. The CAMs are indicting upscale growth occurring into a broken line of storms. One CAM solution suggests two broken lines of storms; one along the cold front and the other along a pre-frontal trof. Once the upscale growth into lines occurs, the severe risk will transition to damaging winds and spin-up tornadoes.

On top of all this, storms will be moving at 50-60 mph so there will be less time that normal to react when a storm approaches. In spite of the fast storm movement, high atmospheric moisture means storms will be prolific heavy rain producers. If storms stall or repeat over the same area due to fronts or boundary interactions, high rainfall rates will create flash flooding due to already wet ground.

In addition to the severe risk will be strong gradient winds. Model soundings are showing 35-40 knots through the mixed layer with 50-55 knots on top. This suggests the potential for sustained gradient winds during the late morning and afternoon of around 30 mph with gusts up to 45 mph...on the cusp of wind advisory. Likewise, the models are showing several hours of wind gusts approaching 50 mph behind the front.

The cold front and severe storms will clear areas east of the Mississippi by mid-evening. The strong gradient winds will slowly decrease the remainder of the night resulting in much cooler and quieter conditions.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 248 PM CDT Wed Jun 10 2026

Quick look at the longer range, a quiet, cooler and tranquil Friday looks in store, then another frontal system takes aim at the region on Saturday with potentially enough forcing to support some strong storms. After that, a well needed reprieve as the storm track gets shunted south and below normal temps infiltrate the area for highs in the 70s Sunday and into early next week. Will have to watch for nuisance clipper like systems for spotty precip chances in the northwesterly steering flow next week.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 625 AM CDT Thu Jun 11 2026

Thunderstorms will impact terminal operations today. Two rounds of storm are anticipated; the first one is high confidence this morning, the other round is slated for the afternoon to early evening but offers some uncertainty due to potential impacts of vigorous morning activity on atmospheric recovery. Numerous TSRA will be seen. The morning storms will produce wind gusts of 35 to 50 knots with swaths of 60-70 kt possible along with embedded tornadoes possible; the afternoon storms may see wind gusts well over 50 knots, a threat for tornadoes and hail. Conditions will be IFR to lower MVFR in the storms. Outside of the storms, some IFR/LIFR stratus and patchy fog will begin the period. Winds outside of storms today and tonight could gust 35-45 kt ahead and behind a cold front. Cold front is progged to be along the Mississippi by 00z/12 with rapidly improving conditions behind it and slowly decreasing winds.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Flood Watch through this evening for IAZ040>042-051>054- 063>068-076>078-087>089-098-099. IL...Flood Watch through this evening for ILZ001-002-007-009- 015>018-024>026-034-035. MO...Flood Watch through this evening for MOZ009-010.